BOOK REVIEWS. 
399 
thereafter every three weeks with Bordeaux mixture, and removal of all affected 
foUage. 
The body of the book contains the usual directions for cultivation and propa- 
gation, and about half the letterpress is taken up with short descriptions of 
varieties and of the author's endeavour to test their value for garden purposes 
in various ways. Amongst others he gives his observations on the number of 
flowers produced per plant of the different varieties. 
The Garden Edition of the work contains sixteen colour photographs and 
rather more than twice as many half-tone plates. The Edition de Luxe contains 
the same half-tone plates and no less than ninety-six colour photographs. If 
we may judge from the latter, it would appear that the full roses, usually called 
exhibition roses in this country, are apt to come rather thinner in the part of 
America where the roses illustrated were grown. Doubtless this may be caused 
by the greater extremes of heat and cold to which the plants are there subjected. 
The book bears evidence of having been prepared mth considerable care, 
and the author's attempt to put a flower value on the different varieties by 
estimating the average number of blooms produced per plant will no doubt 
be read with interest by many in this country. 
Some observers who contribute to the " American Rose Annual " are making 
similar records, but, as the observations at present seem to be made on a 
comparatively small number of plants, it is not surprising that their results 
show discrepancy in detail. If these records are continued no doubt the results 
will tend to approximate and may prove valuable. 
In reviewing the different varieties Captain Thomas often recommends that 
a particular variety should be grown in a special bed, but he gives very little 
indication how such special bed should be prepared. The advice, therefore, is 
not of much assistance to the grower. 
" Keys to the Orders of Insects." F. Balfour- Browne, M.A. 8vo. 58 pp. 
(University Press, Cambridge, 1920.) 7s. 6d. 
This useful and much-needed book is compiled for students with the idea 
of facilitating the " running down " of insects. 
As each authority has a different method of classification, it follows that 
one has to learn each time the particular author's method j but this is done 
away with in the present book. 
The pages are interleaved with blanks for notes. The author has followed 
Lefroy in recognizing twenty Orders, of which only six are fully dealt with. 
A ke'y is given to the Orders of Insects, founded on Comstock's and Lefroy's 
classifications. 
With the help of letters, the key is readily understood and the method 
simple. Then follow keys to the Orders Orthoptera, Rhynchota, Lepidoptera, 
Coleoptera, Diptera, and Hymenoptera. 
Sketches illustrating wing venation are given. 
" The Garden Doctor : Plants in Health and Disease." By F. J. Chittenden. 
8vo. X -f 154 pp. (Country Life Library, London, 1920.) 7s. 6d. net. 
The "Garden Doctor" is intended for the amateur or gardener who is 
closely and intelligently watching and observing the plants in his garden, and 
who wishes to understand and to appreciate the causes and effects of the many 
fungus, insect, or other diseases and pests to which he notices his plants are 
liable, and who is willing to take some little trouble to promote their cure. 
Many amateurs who proclaim their fondness for a garden and for plants 
treat the whole subject of their well-being in a very flippant and dilettante 
way, and far too many so-called gardeners have no real desire for any further 
knowledge than that their great grandfathers have handed down to them, and 
simply scorn the results of scientific investigation. To such as these the " Garden 
Doctor " will obviously be of little use, for they either will not read it or will refuse 
to be guided by it. But to the really keen amateur or gardener who wants to 
be taught and to get behind the outward show of things, and learn the cause 
and the effect and cure, this book will be invaluable. 
From cover to cover it is packed full of the results of close observation and 
experiment, and gives thoroughly practical common-sense advice arising there- 
from. The " Doctor " does not pretend that he can cure every trouble and 
disease, but even in the most difficult cases suggests how the disease is most 
likely to be avoided. 
The writing is unusually concise, particularly in the first two chapters, so that 
every sentence demands, as it so well deserves, the closest attention and thought. 
There are chapters on fungus diseases, with an alphabetical list of all the 
